mountfs
mountfs(&mnt);
static void mountfs(struct mnttab *);
static int mountfs();
static int mountfs(struct vfs *, enum whymountroot, struct vnode *, char *,
error = mountfs(vfsp, why, lvp != NULL ? lvp : svp,
error = mountfs(vfsp, why, devvp, "/", CRED(), 1, NULL, 0);